In the prior art, the earth has a magnetic field. The magnetic field deflects away charged particles that fly toward the earth. Particularly, the magnetic field deflects away charged particles that fly toward the equator of the earth with maximum deflection of the particles when they are travelling perpendicular to the magnetic field. This natural magnetic field provides a degree of protection from charged particles as they approach the earth's surface.
When a space vehicle travels from the earth's surface, protection from the earth's magnetic field is diminished and the performance characteristics of electronic circuits contained within the space vehicle are at increased risk from degradation caused by charged particles that collide with the space vehicle.
Information relevant to attempts to address this problem can be found in U.S. Pat. No. 5,998,868 (Jensen et al.) and U.S. Pat. No. 6,121,672 (Benedetto). However, each of these references requires a physical shield that adds size and weight to the device to be protected.
U.S. Pat. No. 5,998,868 (Jensen et al.) teaches a Radiation Enhanced Chip Encapsulant for use with space based electronic components. Disclosed is a two part shielding system that includes an inner shield, which is preferably an electrically insulating layer, and an outer shield, which is preferably a loaded encapsulant. In operation, when ionizing radiation is directed at a space based electric component including the encapsulant, the outer layer drains energy from the ionizing radiation and absorbs the same. When the component is subjected to ionizing radiation, secondary electrons, typically from the outer shell, may be emitted. The inner layer traps the secondary electrons before they can act on the encapsulated electronic component. However, Jensen does not suggest a shield, or shield system, that deflects ionized particles away from the device to be shielded.
U.S. Pat. No. 6,121,672 (Benedetto) teaches a Raised Pedestal Radiation Shield for Sensitive Electronics. The radiation shield is attached to the device to be protected and is sized and positioned to extend beyond the outer perimeter of the device, such that the sides of the device are also protected. The shield includes a relatively thick central portion, a relatively thin distal portion and an intermediately sized transitional portion. Preferably, the shield is composed of a high-Z material, such as Kovar or a copper/tungsten alloy. While Benedetto also contemplates attaching a shield to both the top and the bottom of the device to be protected, it does not teach or suggest a shield that surrounds the device, such as a magnetic field.